Impulse turbine



Jan. 29; 1929. 1,700,125

L. F. MOODY IMPULSE TURBINE Original Filed May 26, 1923 2 Sheets-Sheet 1 3 hi jym s flow/1%, 4 02/ W Jan. 29, 1929.

L. F. MOODY IMPULSE TURBINE Original Filed May 26, 1923 2 Sheets-Sheet 2 anbemtoz Z0 Y a. #0

y iw W Patented Jan. 29, 1929.

see

.LEw Is FERRY MeonY, or rnrnnnntrnm, rnnusvtvaum.

IMPULSE TURBiNE.

Original application filed May 26, 1923, Serial No; 641,688. Divided and this 21; 1925. Serial No. 57,492.

into the peripheral portions of the buckets and turned by the buckets anddischargedon one side of the rotor.

Further ob ects of the invention P21111011- larly in turning and spreading the flow in gradual and efiicient manner will appear from the following description taken in con- 7 nection with the accompanying drawings in which Fig. 1 is a Vertical sectionalview through a runnerv of a turbine embodying theinven tion.

22 of Fig. 1.

Fig. 3 is a sectional development of buckets of the Fig. 1 runner taken on the cylindrical surface indicated at 33 in Figs. 1 and 2.

Fig. at is a vertical sectional view of a modi lied form of runner. v

Fig. 5 is aplan view of the same, and

Figs. 6, 7 and 8 are sectional views of the runner buckets taken on cylindrical surfaces 66 and 7-7' and conical surface 88 respectively of Figs. 4 and 5.

In the specific embodiment of the invention shown in Figs. 1 to 3 a vertical shaft 10 car-- ries at its lower end the'runner 11 having hub portion 12 carrying the peripheral" cave curves (Fig. 2) from the bucket tips 18 to theline 19 of junction with the hub sur face 14 while the vertical elements taken in vertical cylinders coaxial with the runner are more deeply concave 3) curving forward and then backward to the discharge edge 16. The faces 20 of the buckets as cut by a horizontal plane (Fig. 2) incline backward and outward to form an angle ,8 in their a ncauonaia September entrance portions with relation to tangents to the circle of revolution at the blade tips of the runner, to co-operate properly with the jet which is directed horizontally against the buckets with both tangential-and inward. components, forming anangle 11 with the tangential direction. The angle 0. is specifieallyshown as being less than 45, the jet be- 111g in a more approximately tangential di- 1 rection. I f 1 The water in passing through each runner bucket 13 is simultaneously spread and turned into a backward direction making a small angle B with the tangential'direction; so that its relative velocity is nearly equal and opposite to the motion of the bucket at the point ofdischarge; "and the water is dis charged from each bucket as a thin sheet and F 1g. 2 1s a horizontal sectlonal view on line with but little absolute" velocity ren'iaining in it. The inner lines of flow 22, as'to their meridian components, are curved gradually from a radial inward direction intoanearly axial direction and the outer lines are curved areund from radial inward to a downward andoutward direction. Between these extremes the jet isspread, out gradually in thin sheet form discharging downward in a generally axial direction.

In the runner ofFigs. 1' to 3 the flow is turned from radial toward axialentirely' by the bucket surfaces without contact with the surface 14 of the runner crown or hub 12. The extended hne'of connection between each bucket and thecrown 12 provides a strong support for the buckets and usually a shroud ring will be unnecessary, leaving the exposed edges of the buckets freeand giving easy ac- I cess to the bucket surfaces for grinding and finishing. 3

In the modificationshown in Figs. 5 to 8 the runner hub orcrown 32 has its concave peripheral 7 surface 362 provided with the buckets 33, having concave faces 30 receiving the jet from nozzle 37 at the entrance edge 35 and turning andspreading and decelerating the flow to finally discharge it at 36 as a thin sheet between the inner lines lQ and the outer. lines The entrance edges 35 are contained in a vertical cylindrical surface and the lowor portions of the buckets are extended laterally toprovidefor a wide lateral spreading of the jet as it passes through the bucket. Thefaces 30 of the buckets merge smoothly with the surface 34: of the runner crown and partof the guidance of the water is provided the drawings it is obvious that a pluralityof nozzles may be used and the turbine installed by this surface 34. The shape of'the bucket is shown in Figs. 6, 7 and 8 in developed sec-' tions cut by cylindrical or conical surfaces.

The jet flow is received with inward and tangential components and while it is being spread and turned backward it is guided downward and outward to a generally axial discharge. The buckets 33 instead of inclinlng. outwardly and forwardly at their entrance p0rt1ons35 are nearly radial at these portions asviewed in horizontal section or inclining slightly backward and outwarc. Progressing inwardly toward the hub these buckets curve inward and backward on I smooth lines which reach a substantially tanential direction at the line of mergence with the crown surface 345- In both the runners shown successive buckets overlap in axial projection'as indi cated in Figs. 2, 3, 5, 6 and 'Z'so that the discharge edge of one bucket lies under the upper entrance portion of the following; bucket. While only one nozzleis shown inin any desired setting adapted for instance to maintain a partial vacuum in the runner, chamber. The ets may be dlrected at any desiredangle so as to vary the relative 1nward and tangential components to suit different conditions and without departing from the principle of the 1nvent1on'v'ar1ous 1110(l1- fications be resorted to within the scope- 1 securing a highspecific speed, it will be, ad. vantageous in many cases to combine the forward inclination ofthelbuckets of Fig. 2 with the lateral extension of the discharge edges of the buckets'shown in Fig. 4. This may be done either by modifying the runner of Figs. 1 and 2 to extend the outflow edges of the blade outwardly from the axis to a greater diameter than the inflow edges or bymodifying the runner of Figs. 4 and 5 so as to give the entrance edges of the vane a forward angle of inclination with respect to the radius similar to'thatshown in 2. lVhen the laterally extended buckets are used, this, outward extension may for high specific speeds be carried. to the extent where the buckets willextend under and beyond'the nozzle, the. entrance portion of the bucket being cut away sufliciently to clear the nozzle. It is-desirable tohave the nozzle orifice as close as possible to. the entrance edges ofthe buckets in order to minimize the length of free path traversed by. the jet between the orifice and the, bucket edges- The nozzles indicated in the figures are of the type in ywhic h the sizeof the jetiis. controlled by a central needle. The needle may be of relatively short form having the sides of its i311) converge at a considerable angle'at the point, thus permitting the nozzle to be placed close to the vane edges.

(This application is a dlvislon of my application, No. 641,688, filed MayQG, 1923, now

Patent No. 1,554,574.)

I claim;

i 1. In an impulse turbine means for forming a cylindrical free jethaving itsaxis substantially in a plane perpendicular to the runner axis, and a runner having buckets receiving said. jet and turning all of it toward the axial direction and discharging it on one side of the runner, the flow between adjacent buckets having a free surface, said jet being more tangential than radial said runner.

2111 an impulse turbine means for formwith respect to ing a-cylindrical free jethaving'its axis substantially in a plane perpendicular to the runner axis, and a. runner having buckets receiving said et and turning. all of it toward the axial direction and spreading it laterally so that the inner lines of the discharge have inward components and the outer flow lines have outward components, said jet being of entrance to said buckets, said jet being more tangential thanradial with relation to said runner and theflow between adjacent buckets havlng a free surface.

0. In an impulse turbine means for-form 4... in an impulse turbine means for forming a cylindrical free et having its axis sub stantially in a plane perpendicular to the runner axis, and a runner having buckets receiving said et with a free surface for the flow between adjacent buckets and turning all of it toward the axial direction and spreadingit laterally so'that the inner lines of the discharge h ave inward components and the outer flow lines have outward components, said jet havlng both tangential and radial 'components at the point of entrance to said buckets and the tangential component being greater,

than the radial component.

.5. In an impulse turbine means for form-- ing a cylindrical free jet having its axis substantially in a plane perpendicular to the: runner axis, and a. runner having buckets.

with faces directed substantially radially at their entrance portions and turning all of said et to'one side of said plane, the fi0wbetween adjacent buckets having afree. surface.

6. in an impulse turbine means for form ing-a cylindrical free jet having its axis substantially in a plane perpendicular to the runner 3X18, and a runner having buckets with faces directed substantially radially at their entrance portions and turning'all of sald et to one side of said plane, said et at the point of entrance to the buckets having" both radial and tangential components and the flow between ad acent buckets having a free surface.

7. In an impulse turbine means for form radial at their outer entrance portions and turning all of said jet to one side of said plane and discharging it in a generally axial direction, said jet at the point of entrance to the buckets being substantially tangential, and the flow between adjacentbuckets having a free surface. i

S, In an impulse turbine, in combination, means for forming a cylindrical free jet comprising a nozzle with a central adjustable needle and directing said jet in a plane perpendicular to the runner axis and a runner having buckets withvthe entrance portion of their faces inclined at a forward anglewitli respect to the radial direction at their inner portions and being substantially radial at their outer entrance portions and discharging all of said jet on one side of the runner, the flow between adjacent buckets having a free surface. I

9. In an impulse turbine, in combination, means for forming a cylindrical free jet comprising a nozzle with a central adjustable needle and directing said jet in a plane perpendicular to the runner axis in a more tangential direction than radial, and a runner receiving said jet and discharging all of said jet on one side of the runner, and the flow between adjacent buckets having a free surface.

10. In an impulse turbine means for forming a cylindrical free jet having its axis substantially in a plane perpendicular to the runner axis and a runner having buckets receiving said jet and discharging all of it on one side of the runner, said jet having a greater tangential than radial component at the point of entrance to said buckets, and the flow between adjacent buckets having a free surface.

11. In an impulse turbine means for forming a cylindrical free jet having its axis substantially in a plane perpendicular to the runner axis, and a runner having buckets receiving said jet and spreading it laterally so that a portion of said jet is directed in the axial direction at discharge and a portion is directed outwardly from the axis, said jet having a greater tangential than radial component at the point of entrance to said buckets, and the flow between adjacent buckets'having a free surface;

12; In an impulse turbine means forforminga cylindrical freejet havingits axis substantlally in plane perpendicular to the runner axis but havinga dlrection more near;

ly tangential than radial in said plane,and a runner having buckets with the inner portion of their faces inclined forward of theradi'al direction and with the outer entrance portion of their faces substantially radial and turn-' ingall of said jet to one side of said plane, the flow between adjacent buckets having a free surface. l

13. In an impulse turbine the combination with a rotor having a vertical axis and buckets with substantially radially directed surfaces and adapted to turn the entire flow from horizontal-downward to one side of said rotor, of a nozzle forming a horizontal cylindrical jet and directing it substantially tangentially'against the substantially radially directed suraces of said buckets so that the turbine will havea moderate specific speed,

14. In an nnpulse'turbine means for formlng a cylindrical free et having its axis substantially in a plane perpendicular tothe runner axis, and a. runner having buckets receiving said jet and turning all of it to,- ward the axial direction and discharging it on one side of the runner, the flow between adjacentbuckets having a free surface, the axis of said jet subtending a small angle to the tangential direction at the entrance edge of said buckets. V

15. In an impulse turbinean adjustable needle nozzle for forming a cylindrical free jet having its axis substantially in a plane perpendicular to the runner axis, and a runher having buckets receiving said jet with a free surface for the flow between adjacent buckets and turning all of it toward the axial direction and spreading it laterally so that the inner lines of the discharge have 111-- ward components and the outer flow lines have outward components, said having both tangential and radial components at the point of entrance to said buckets and the tangential component being greater than the ra-v dial component. I

16. In an impulse turbine means for forming a cylindrical free jet having its axis substantially in a plane perpendicular to the runner axis but having a dlrectlon more nearly tangential than radial in said plane,

1 ill) Cir direction at a small angle to the radius at their entrance edges and adapted to turn the entire flow from horizontal downward to one side of-said rotor, of a nozzle forming a horizontal cylindrical jet and directing it with a tangential .component against the substantially radially directed surfaces of said buckets so that the turbine will have a mod erate specific speed.

18. The combination set forth in claim 1 having the buckets provided with a discharge edge which has at least a. portion curved in plan View. a

19. The combination as set forth in ,claim 1 having the buckets provided With a discharge edge which in plan view has its outer portion curved forwardly hile its inner portion is substantially straight and radially disposed,

20. The combinationas set forth in claim 1 having the buckets shaped so that in a: circular section parallel to the runner axis the bucket is disposed substantially entirely backward of the entrance portion. a

21. The combination as set forth in claim 5 further characterized by having the buckets provided with a discharge edge which has at least a-portion curved in plan view.

22. The combination as set forth in claim tially straight and radially disposed.

23. The combination as set forth in claim 5 further characterized by having the buckets shapedso that in a circular section parallel to the runner axis the bucket is disposed substantially entirely backward of the entrance portion.

24. The combination as set forth in claim 8 further characterized by having the buckets provided with a discharge edgewhicl'i has at least aportion curved in plan View,

25; The combination as set forth in claim 1 further characterized in that said buckets I have a greater radial than ani al extent.

26. The comb nat on as set forth in claim 12 further characterized in that said buckets have an entance edge which in elevation is disposed radially inwardly of the outermost portion of the buckets.

2 8, The co nbinationas set forthin claim 1 further characterized by having a. jet Which is variable While still preserving its cylindrical form and having buckets overlapping each other in projection.

29, The combination as set forth in claim 12 further characterized by having a jet which is variable While still preserving its cylindricalform and having buckets overlapping each other in axial projection.

30. The combination as set forth in claim 12 further characterized in that said buckets overlap each other in axial projection and have a greater radial than a rial extent While the size of the cylindrical, jet is adapted to be varied While still preserving its cylindri- & form.- I

EWIfi FERRY MOOD 

